Brake operated transmission neutralizer

ABSTRACT

A vehicle which has a transmission having forward and reverse control means in which the forward and reverse control means is connected to a bracket member on the manual control lever to shift the transmission from neutral to forward or reverse; the vehicle is further equipped with a brake mechanism actuated by a pivoted brake pedal which is connected by means of a return spring to the bracket member attached to the control lever; the spring normally tends to constantly urge the control lever in the neutral position; when in tension a lost motion connection is provided between the spring and the bracket member to allow the bracket member to be pivoted by shifting of the direction control lever without loading the spring; the mechanism functions such that, when the brake is applied, the lost motion connection is taken up and the spring is tensioned causing the direction control lever to return to neutral; the spring and the bracket member on the control lever further provides an override means permitting the tractor transmission to be shifted into forward or reverse before the brake is released by stretching the spring to obtain vehicle motion prior to complete brake release.

United States Patent Blaauw 1 Feb..29,1972

[54] BRAKE OPERATED TRANSMISSION NEUTRALIZER [72] Inventor: AndrewBlaauw, Winneconne, Wis.

[73] Assignee: J. 1. Case Company, Racine, Wis.

[22] Filed: Oct. 26, 1970 [21] Appl.No.: 83,752

3,539,040 11/1970 Edwards... ..l92/4B Primary ExaminerBenjamin W. WycheAt!0rney-Cullen, Settle, Sloman & Cantor [5 7] ABSTRACT A vehicle whichhas a transmission having forward and reverse control means in which theforward and reverse control means is connected to a bracket member onthe manual control lever to shift the transmission from neutral toforward or reverse; the vehicle is further equipped with a brakemechanism actuated by a pivoted brake pedal which is connected by meansof a return spring to the bracket member attached to the control lever;the spring normally tends to constantly urge the control lever in theneutral position; when in tension a lost motion connection is providedbetween the spring and the bracket member to allow the bracket member tobe pivoted by shifting of the direction control lever without loadingthe spring; the mechanism functions such that, when the brake isapplied, the lost motion connection is taken up and the spring istensioned causing the direction control lever to return to neutral; thespring and the bracket member on the control lever further provides anoverride means permitting the tractor transmission to be shifted intoforward or reverse before the brake is released by stretching the springto obtain vehicle motion prior to complete brake release.

9 Claims, 3 Drawing Figures BRAKE OPERATED TRANSMISSION NEUTRALIZERBACKGROUND AND SUMMARY OF THE INVENTION The present invention relates ingeneral to vehicle transmission control mechanisms and more inparticular to a combined transmission and brake control mechanism for avehicle.

In vehicles employing a hydrostatic transmission, as the torquetransmitting driving force for the traction wheels of the vehicle, it ishighly desirable that the transmission be shifted to a neutral positionprior to braking of the traction wheels of the vehicle so as to avoidbraking against engine power transmitted to the traction wheels by meansof the hydrostatic transmission. It is conventional practice to providemanually operable control mechanisms for controlling the output of thedrive pump of the hydrostatic transmission as well as the directionalfluid flow in order to control directional movement of the vehicle.These control mechanisms are arranged such, as to require mechanisms toput the transmission into neutral before applying the vehicle brakes. Ininstances where the operator of the vehicle fails to actuate thedirectional control mechanism for any reason whatsoever, or in the eventof an emergency where there is no time to affect manual actuation of thecontrol mechanism, the operator will brake the vehicle motion againstthe engine power transmitted to the hydrostatic transmission, resultingin damage to the transmission as well as stalling of the engine.

It has been proposed herebefore to provide an integrated mechanismbetween the directional control mechanism and the brake mechanism of thevehicle to cause automatic return of the directional control mechanismto the neutral position to disconnect the transmission from the tractionwheels when the brake mechanism is actuated. However, in these knownarrangements, no effective means have been provided to permit actuationof the direction control mechanism prior to release of the brakes inorder to provide tractive power to the traction wheels of the vehiclebefore complete release of the brakes, which is highly desirable instarting movement of the vehicle on a hillside to prevent the vehiclefrom rolling downwardly when the brakes are released. Thus, in the knownmechanisms of this kind, the vehicle directional control mechanisms arelocked in neutral and remain in neutral as long as the brakes areapplied, permitting shifting into forward or reverse only after completerelease of the brakes.

The present invention provides an improved mechanism of the type whichinterconnects the transmission directional control mechanism with thebrake actuating mechanism of the vehicle in such fashion as to permitshifting of the directional control mechanism prior to complete releaseof the brakes.

Accordingly, the primary object of the present invention is to providean improved means for coupling the brake actuating mechanism of thevehicle with the directional control mechanism of the vehicletransmission, such that, upon actuation of the brake mechanism thetransmission of the vehicle will be automatically returned to neutraland wherein the interconnecting means incorporates a tension springconnection permitting the directional control mechanism to be shifted ina selective drive position prior to release of the brake mechanism toprevent runaway of the vehicle.

The present improved mechanism includes a manual control lever forselective directional control of the transmission of the vehicle, whichhas a bracket member attached thereto for pivotal movement with thecontrol lever around an axis. The bracket member is attached to acontrol linkage which is connected to the shift actuator of thetransmission so that by selective positioning of the control lever, theactuator will be positioned to cause rotation of the transmission in therespective direction. The bracket member of the control lever is furtherconnected to the bracket member of the end of the brake pedal returnspring, the other end of which is connected to the brake pedal of thevehicle, which is operable to retain the bracket member, and thus thecontrol lever, in a neutral position. The return to neutral spring isconnected to the bracket member of the control lever by means ofalost-motion connection to permit actuation of the directional controlmechanism prior to the engagement of the brake mechanism without havinga reactive force from the spring.

The foregoing objects and advantages and other novel features of thepresent invention will become more fully apparent by reference to thefollowing detailed description of a preferred embodiment of theinvention as illustrated on the attached sheet of drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustratesa preferred embodiment of the invention in which:

FIG. I is a side elevation of a vehicle in which the present inventionis embodied for illustrating purpose;

FIG. 2 is an enlarged top plan view of the present improved interrelatedcontrol mechanism shown in the neutral position; and

FIG. 3 is a schematic, further enlarged illustration of the functionalcharacteristic of the present improved interrelated control mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the attacheddrawings hereof, it will be seen that the present invention, forexample, is depicted as being incorporated in a tractor vehicle,generally indicated by the reference numeral 10, including a frame 11supported on front mounted steerable wheels 12 (only one of which isshown) steerable by means of a steering wheel 13 conventionallyconnected by a linkage to the front wheels 12.

The rear end of the frame 11 is supported on traction wheels 15 (onlyone of which is shown), which are conventionally drivingly connected tothe prime mover 16 of the tractor 10 for rotation around an axle 17. Therear end of the frame 11 further supports an operator station 19including a seat 21.

The traction wheels 15 are driven from the engine 16 by means of atransmission indicated at 18 which may be a hydrostatic unittransmission to drive the traction wheels at various selective speedranges in forward or reverse direction.

The traction wheels 15, as is customary, are provided with brakes (notshown) actuated by foot operated brake linkage which includes a lever 20pivoted at its lower end to the frame 1 l and provided at the upper endwith a brake pedal 22. The lever 20 is connected by means of a brake rod24 to the customary brake actuating lever 26 so that upon pressure onthe foot pedal 22, the lever 20 will be pivoted to move the brake rod 24longitudinally which pivots the brake actuating lever 26 for applicationof the brakes in customary fashion.

The transmission 18 is selectively rotatable in either forward orreverse direction provided for by respective positioning of a directionpositioning valve 28 which has a valve actuating stem 30 for connectionto a link member 32. The directional positioning valve 28 is actuated bymeans of a manual control lever 34 disposed within reach of the operatorof the tractor, which is attached to the upper end of a pivot shaft 36suitably supported for pivoting movement within the tractor housing. Thelower end of the pivot shaft 36 of the control lever 34 is provided witha pivot member 38 in the form of a bracket, attached thereto forrotation with the pivot shaft when the control lever is manipulated.

AS seen in FIGS. 2 and 3, the bracket like pivot member 38 is shapedsubstantially triangular in plan view with one apex being attached tothe control lever shaft 36 for pivotal rotation of the pivot member 38with the control lever shaft 36 when the control lever is manipulated.The other end of the link member 32 of the directional positioning valve28 is pivotally connected at 33 to another. apex of the pivot member 38adjacent the pivot shaft connection. The third apex of the triangularshaped pivot member 38, forwardly of the control lever pivot shaft 36and normally in linear alignment therewith, is connected to one end of abrake pedal return spring 40 which other end is connected to an armextension 42 of the brake pedal 22 such, that the longitudinal axis X"of the spring 40 normally, that is in neutral position of the controllever 34, is in linear alignment with and intersecting the pivot axis Yof the pivot shaft 36 as shown in FIGS. 2 and 3.

The brake pedal return spring 40 is connected to the pivot member 38 bymeans of a lost-motion connection comprising a longitudinal slot 44, insuch a manner that, in the normal or neutral position of the controllever 34, the hood end 41 of the spring 40 abuts against the inner endof said slot 44, as likewise shown in FIGS. 2 and 3.

The upper end of the control lever pivot shaft 36 extends through acontrol console 46 provided on the housing of the tractor adjacent thesteering wheel 13 and is therein provided with a pointer 48 adapted forpivotal rotation with the pivot shaft 36 upon manipulation of thecontrol lever 34. The pointer 48 is adapted to align with a selected oneof indicias 50 provided on the control console 46 to thereby indicate tothe operator of the vehicle the respective drive position of thetransmission 18.

The operation of the present improved, interconnected brake anddirection control linkage is as follows: when the direction controllever 34 is in a neutral position and the brake pedal 22 in the unbrakedposition, there will be no tension on the return spring 40. In thisposition, which is shown in FIG. 2 and in solid lines in FIG. 3, thereturn spring 40 is in direct linear alignment with the central pivotaxis Y of the control lever pivot shaft 36 and the end 41 of the springis disposed in abutment against the inner rear surface of the slot 44 inthe pivot member 38.

When the direction control lever 34 is moved to either the forward orreverse driving position, indicated by the indicias 50 on the controlconsole 46, the pivot member 38, which is attached to the control leverpivot shaft 36, is rotated in the same direction as the control lever34, thereby longitudinally pulling or pushing the link member 32 toreposition the direction positioning valve 28, due to the pivotalconnection at 33 to the pivot member 38.

With particular reference to FIG. 3, when the control lever 34 is movedto the forward position indicated by the indicia F" on the controlconsole 46, the pivot member 38 is pivoted to he position 38a indicatedin dot and dash lines in FIG. 3. This causes angular repositioning ofthe return spring 40 relative to the previous aligned position with thecentral pivot axis "Yof the control lever pivot shaft 36, causingmovement of the spring end 41 within the slot 44, however, in thisposition the spring 40 will not be subjected to a tension load.

If the operator now applies the brake, by depression of the foot pedal22, the spring 40 is placed under tension, forcing the pivot member 38in the opposite direction towards its initial neutral position due tothe abutment of the spring which now abuts against the outer end of theslot 44 to thereby return the control lever 34 to the neutral positionand, consequently, the direction positioning valve linkage 32. In thisbrake-applied position, the spring hook 41 at the end of the springremains in the forward end of the slot 44 as long as the foot pedal 22is depressed.

AS normally provided for, the neutral position of the control lever 34may be locked in place by means of a spring detent or the like (notshown). Thus, as soon as the brake application is started by depressionof the foot pedal 22 the control lever 34 is automatically forced intoneutral, from either its forward drive position indicated by the numeral38a in FIG. 3, or the reverse drive position indicated by the numeral38b, to thereby positively prevent braking against engine power.

When starting the tractor l0, normally the brake will be released first,when the tractor is on level ground. However, if the tractor I0 ispositioned or has stalled on an incline or is otherwise in a precariousposition, the driving position may be engaged prior to the release ofthe brake by moving the control lever 34 in the required drive position,thus manually overriding the force of the spring 40 which tends to urgethe pivot member 38 in aligned neutral position. Thus, tractive powermay be supplied to the traction wheels while the brakes of the vehicleare still applied, to prevent the vehicle from rolling away if thebrakes were released prior to the application of tractive power to thetraction wheels 15.

In the neutral position of the mechanism, when pressure is 1 releasedfrom the brake pedal 22 the spring end 41 returns to the rear end of theslot 44, as in FIG. 2.

Thus, it will be seen from the foregoing description in connection withthe attached drawings that the present invention provides an improvedmechanism including means to interlock and overridingly couple thebraking mechanism with the directional control mechanism of the vehicle.The present improved interconnecting mechanism assures that the brakesof the vehicle will not be applied while engine power is transmitted tothe traction wheels, but which, on the other hand, provides thattractive power may be supplied after braking, when the brakes of thevehicle are still applied, as a safety measure to prevent the vehiclefrom running away, when the vehicle is disposed on an incline.

While the present invention has been shown and described in connectionwith a preferred embodiment, it will be obvious to a person skilled inthe art that various changes in structure and arrangement and minormodifications may be made without departing from the spirit andessential characteristic of the invention as defined by the scope in theappended claims.

I claim:

1. In combination with a vehicle having a prime mover and tractionwheels including brakes and a transmission operably connected betweensaid prime mover and said traction wheels; a brake actuating mechanismconnected to the brakes of said traction wheels and a manually operabledirection selector control lever for said transmission pivotally mountedon said vehicle for movement between a forward and reverse driveposition from a central neutral position; the improvement comprising: apivot member mounted on said control lever for pivotal movementtherewith; a link pivotally mounted on said pivot member and operablyconnected to said transmission for placement of said transmission in therespective drive position, corresponding to the selective position ofsaid control lever; said brake mechanism including a brake rod connectedto said brakes at said traction wheels and to a brake pedal; tensionmeans connected between said brake pedal and said pivot member tonormally retain said brake pedal in an inoperative position and normallydisposed along an axis incidental with the neutral position of saidcontrol lever; and means permitting displacement of said tension meansfrom said axis towards both sides thereof upon shifting of said controllever to the forward or reverse drive position without tensioning saidtension means, whereby said tension means is operable to return to saidaxis incidental with the neutral position of said control lever whensaid tension means is tensioned by depression of said brake pedal whilesaid control lever is in a selected drive position.

2. In the combination as defined in claim 1, said means permittingdisplacement of said tension means from said axis comprising alost-motion connection.

3. In the combination as defined in claim 2, said control lever having apivot shaft mounted for pivotal movement around an axis in said vehicle,and said pivot member comprising a bracket secured to said pivot shaft,said link being mounted on said bracket to one side of said pivot shaftand said tension means being mounted on said bracket forwardly of saidpivot shaft along an axis normally intersecting the axis of said pivotshaft.

4. In the combination as defined in claim 3, said lost-motion connectioncomprising a slot in said bracket and the end of said tension meansconnected to said bracket being normally disposed in the rear end ofsaid slot when said control lever is in a neutral position and the brakepedal is in inoperative position to thereby permit pivotal movement ofsaid bracket with said pivot shaft when said control lever is shifted toa selective drive position without tensioning of said tension means.

5. In the combination as defined in claim 4, said tensioning meanscomprising a coil spring.

such as 6. In a return-to-neutral control mechanism for use in a vehiclehaving a transmission and a brake actuating mechanism, said controlmechanism comprising: a control lever having a shaft rotatably mountedin said vehicle for pivotal movement of said control lever around anaxis between a first and a second drive position from a neutral centralposition; said pivot shaft having a bracket member mounted thereon forrotation therewith; a first linkage means connecting said bracket memberwith said transmission; said brake actuating mechanism comprising abrake rod operably connected to a brake pedal; elongatable secondlinkage means connecting said brake pedal with said bracket member andnormally disposed along an axis intersecting the axis of said shaft whensaid control lever is in said neutral position; means comprising alost-motion connection between said elongatable second linkage means andsaid bracket member to permit pivotal movement of said bracket memberwithout elongating said second linkage means and displacing said axisfrom the intersecting position with said shaft axis; said lost-motionconnection being taken up when said brake pedal is depressed to therebyelongate said second linkage means and return said control lever bymeans of connection to said bracket member to the neutral position froma selective drive position and into aligned intersecting position withsaid shaft axis.

7. In the control mechanism as defined in claim 6, said bracket memberin cooperating relationship with said second linkage means and saidlost-motion connection providing an override means to permit shifting ofsaid control lever into a selective drive position when said brake pedalis depressed prior to release of said brake pedal.

8. in the control mechanism as defined in claim 7, said lostmotionconnection comprising a slot in said bracket member and said secondelongatable linkage means comprising an energy storing tension memberhaving one end slidingly disposed in said slot normally in the rear endthereof when said control lever is in neutral and said brake pedal is ininoperative position; said one end being adapted to be displaced in saidslot towards the front end thereof upon pivotal movement of said bracketmember by shifting of said control lever in either first of second driveposition to thereby permit loading of said energy storing tension memberunless the brake pedal is depressed.

9. In the control mechanism as defined in claim 8, said energy storingtension member comprising a coil spring.

1. In combination with a vehicle having a prime mover and tractionwheels including brakes and a transmission operably connected betweensaid prime mover and said traction wheels; a brake actuating mechanismconnected to the brakes of said traction wheels and a manually operabledirection selector control lever for said transmission pivotally mountedon said vehicle fOr movement between a forward and reverse driveposition from a central neutral position; the improvement comprising: apivot member mounted on said control lever for pivotal movementtherewith; a link pivotally mounted on said pivot member and operablyconnected to said transmission for placement of said transmission in therespective drive position, corresponding to the selective position ofsaid control lever; said brake mechanism including a brake rod connectedto said brakes at said traction wheels and to a brake pedal; tensionmeans connected between said brake pedal and said pivot member tonormally retain said brake pedal in an inoperative position and normallydisposed along an axis incidental with the neutral position of saidcontrol lever; and means permitting displacement of said tension meansfrom said axis towards both sides thereof upon shifting of said controllever to the forward or reverse drive position without tensioning saidtension means, whereby said tension means is operable to return to saidaxis incidental with the neutral position of said control lever whensaid tension means is tensioned by depression of said brake pedal whilesaid control lever is in a selected drive position.
 2. In thecombination as defined in claim 1, said means permitting displacement ofsaid tension means from said axis comprising a lost-motion connection.3. In the combination as defined in claim 2, said control lever having apivot shaft mounted for pivotal movement around an axis in said vehicle,and said pivot member comprising a bracket secured to said pivot shaft,said link being mounted on said bracket to one side of said pivot shaftand said tension means being mounted on said bracket forwardly of saidpivot shaft along an axis normally intersecting the axis of said pivotshaft.
 4. In the combination as defined in claim 3, said lost-motionconnection comprising a slot in said bracket and the end of said tensionmeans connected to said bracket being normally disposed in the rear endof said slot when said control lever is in a neutral position and thebrake pedal is in inoperative position to thereby permit pivotalmovement of said bracket with said pivot shaft when said control leveris shifted to a selective drive position without tensioning of saidtension means.
 5. In the combination as defined in claim 4, saidtensioning means comprising a coil spring.
 6. In a return-to-neutralcontrol mechanism for use in a vehicle having a transmission and a brakeactuating mechanism, said control mechanism comprising: a control leverhaving a shaft rotatably mounted in said vehicle for pivotal movement ofsaid control lever around an axis between a first and a second driveposition from a neutral central position; said pivot shaft having abracket member mounted thereon for rotation therewith; a first linkagemeans connecting said bracket member with said transmission; said brakeactuating mechanism comprising a brake rod operably connected to a brakepedal; elongatable second linkage means connecting said brake pedal withsaid bracket member and normally disposed along an axis intersecting theaxis of said shaft when said control lever is in said neutral position;means comprising a lost-motion connection between said elongatablesecond linkage means and said bracket member to permit pivotal movementof said bracket member without elongating said second linkage means anddisplacing said axis from the intersecting position with said shaftaxis; said lost-motion connection being taken up when said brake pedalis depressed to thereby elongate said second linkage means and returnsaid control lever by means of connection to said bracket member to theneutral position from a selective drive position and into alignedintersecting position with said shaft axis.
 7. In the control mechanismas defined in claim 6, said bracket member in cooperating relationshipwith said second linkage means and said lost-motion connection providingan override means to permit shiftinG of said control lever into aselective drive position when said brake pedal is depressed prior torelease of said brake pedal.
 8. In the control mechanism as defined inclaim 7, said lost-motion connection comprising a slot in said bracketmember and said second elongatable linkage means comprising an energystoring tension member having one end slidingly disposed in said slotnormally in the rear end thereof when said control lever is in neutraland said brake pedal is in inoperative position; said one end beingadapted to be displaced in said slot towards the front end thereof uponpivotal movement of said bracket member by shifting of said controllever in either first of second drive position to thereby permit loadingof said energy storing tension member unless the brake pedal isdepressed.
 9. In the control mechanism as defined in claim 8, saidenergy storing tension member comprising a coil spring.